Described is a distributed peer-assisted multicast content delivery system (e.g., a multiparty conferencing application) that uses an adaptive link rate control protocol to discover and adapt to an arbitrary topology quickly and converge to efficient link rate allocations allowed by an underlying network. Link rates are regularly obtained and used to determine trees for sending packets to other nodes. Network coding is used to implement data multicast so that mixtures (i.e., linear combinations) of the packets are transmitted in the network. The redundant packets may be differentiated from non-redundant (“innovative”) packets such that network conditions may be measured by link innovation and/or session innovation.